<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>初始化 state - 紫霞仙子</title>
</head>
<body>
    <div id="root"> </div>

    <script src="../js/react.development.js"></script>
    <script src="../js/react-dom.development.js"></script>
    <script src="../js/babel.min.js"></script>

    <script type="text/babel">
        //数据
        // let data = {
        //     isNight: false
        // }

        class App extends React.Component{
            //1. 声明 state
            // state = {
            //     isNight: true
            // }

            //2. 构造方法
            constructor(){
                super();//必须要加的
                this.state = {
                    isNight: true
                }
            }

            //render 方法内部, this 是组件的实例对象
            render(){
                //返回虚拟 DOM 对象.  
                return <h1>至尊宝, 我是 {this.state.isNight ? '青霞' : '紫霞' }仙子</h1>
            }
        }

        ReactDOM.render(<App />, document.querySelector("#root"));

    </script>
</body>
</html>